Laser system for weapon fire simulation

ABSTRACT

A weapon direct fire kill simulator system in which a laser transmitter means of dual mode, narrow and broad beam projection, capability, a hit receiver-actuator means and hit indication means all fixed to a weapon to be simulated and having a trigger switch are combined with a man target means having retroreflective apparel or patches to reflect the narrow fire beam back to the hit receiver-actuator and combined also with a 360* kill detector-actuator means to receive the kill beam to actuate a kill indicator alarm also made a part of the man target wearing apparel. The invention also contemplates a timing means and adjustable range gate means to disable the system when the target is beyond the simulated weapon&#39;&#39;s range, comparator means to eliminate noise signals below the value of the hit indicator signals, and disabling means to inactivate a man target once hit. In composite, the system provides immediate hit indication to the trainee and kill indication to the man target while also correcting for weapon characteristics.

it tates atent [191 Marshall Aug. 12, 1975 LASER SYSTEM FOR WEAPON FIRESIMULATION [75] Inventor: Albert H. Marshall, Maitland, Fla.

[73] Assignee: The United States of America as represented by theSecretary of the Navy, Washington, DC.

[22] Filed: June 24, 1974 [2!] Appl. No.: 482,544

52 us. 01. ..35/2s;273/101.1 51 Int. Cl. F4lg 3/26 581 Field of Search35/25; 273/101.1

[56] References Cited UNITED STATES PATENTS 3,657,826 4/1972 Marshall etal. 35/25 3,847,396 ll/l974 Ashford 35/25 X Primary Examiner-Robert W.Michell Assistant E.\'aminer.lohn H. Wolff Attorney, Agent, orFirm-Richard S. Sciascia; John W. Pease [57 l ABSTRACT A weapon directfire kill simulator system in which a laser transmitter means of dualmode, narrow and broad beam projection, capability, a hitreceiveractuator means and hit indication means all fixed to a weapon tobe simulated and having a trigger switch are combined with a man targetmeans having retroreflective apparel or patches to reflect the narrowfire beam back to the hit receiver-actuator and combined also with a 360kill detector-actuator means to receive the kili beam to actuate a killindicator alarm also made a part of the man target wearing apparel.

The invention also contemplates a timing means and adjustable range gatemeans to disable the system when the target is beyond the simulatedweapons range, comparator means to eliminate noise signals below thevalue of the hit indicator signals, and disabling means to inactivate aman target once hit.

In composite, the system provides immediate hit indication tothe,.trainee and kill indication to the man target while also correctingfor weapon characteristics.

9 Claims, 5 Drawing Figures PATENTED 2W5 3, 898.7 37

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LASER SYSTEM FOR WEAPON FIRE SIMULATION BACKGROUND OF THE INVENTION Theinvention relates to the field of education and training in direct fireweapons and to the field of simulation relating to a man vs man combatsystem.

In order that military combat practices in the field of direct fireweaponry may be carried out in a realistic, yet economical fashion, suchas to provide effective training comparable to the use of operationalequipment and live round ammunition, past efforts have been directed tovarious forms of simulation equipment of substantial weight, bulk andcomplexity. Thus, in the past radiation transmitters have been employedfor emitting a narrow beam of optical radiation, the transmitter beingmounted to be aimed with the weapon simulated and combined with detectormeans oriented to a target screen and hit or miss indicator means in theform of audio or visual signal means. In man-to-man combat simulationsystems of this type the man must be covered with numerous detectorswhich are easily destroyed or interfered with on military maneuvers.Also a radio pack is required to transmit kill data to the traineefiring his weapon. The use of a woven vest of optic fibers to reduce thenumber of detectors has been tried with lack of success because the vestbecomes fragile and presents a more stringent signal-to-noise problem. Abasic system of laser beam transmitter and man target apparel ofretroreflective material provides only an indication of kill to thetrainee firing the weapon but provides no kill data or indication to theman target and no disablement of the man target.

SUMMARY OF THE INVENTION The invention comprises an arrangement of adual mode laser transmitter and a receiver, together with hit indicatormeans in integral relationship with a weapon to be simulated havingswitch means for operating the transmitter in hit mode beam when thetrigger switch is actuated. The invention comprises in associationtherewith a man target (simulating man to man engagement) wherein theman target is provided with apparel or patches of retroreflectormaterial to reflect the fire beam to the receiver-actuator and therebyactuate the transmitter to the second or broad beam kill mode. The broadbeam is received by kill receiver-actuator (detector) means on thehelmet of the man target to actuate an alarm system which can only beshut off by turning a key in a circuit which eliminates the man targetfrom further competition.

The invention also contemplates range gate means for inactivating thelaser transmitter when the target is beyond the weapon range, andvoltage comparator means for eliminating noise signals of a level belowthe hit signal level.

DESCRIPTION OF THE DRAWING FIG. 1 is a schematic functional presentationof a man-to-man wepon fire kill simulator system incorporating theinvention;

FIG. 2 is a schematic diagram of circuit details of the system of FIG.1;

FIG. 3 is a schematic diagram of a suitable amplifier and avalanchedetector employed in the system of FIGS. 1 and 2;

FIG. 4 shows a suitable circuit for the kill detector, alarm system andkey interlock employed to indicate a kill; and 4 FIG. 5 is a schematicof a suitable integrated circuit timer and light emitting diode used inthe circuit of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, there isshown two fighting men, trainees, equipped with a weapon fire simulatorsystem incorporating the invention. The trainees and 12 are identicallyequipped and for convenience in reference, identical equipment will begiven the same numerical identification for each item of equipment.Thus, trainees l0 and 12 are provided with helmets 14 having 360 killreceiver-actuators 16 for laser beams, alarm means 18, jackets 20 ofretroreflective material and a laser type weapon simulator 22 having atrigger 24, a fire beam (narrow beam) laser 26, kill beam (wide angle)laser 28, hit receiver-actuator 30, hit indicator 32, power source means34, and comparator and gating circuit means 36 to exclude noise signalsand input signals beyond the intended range of the weapon.

Also shown in FIG. 1 are the several rays which result from the firingand hitting of a man target. Thus, actuation of the trigger 24 energizesthe fire beam laser 26 which produces a narrow fire beam 38 which uponstriking the retroreflective jacket 20 of the target man isretroreflected (beam 40) to actuate the hit receiveractuator 30.Receiver-actuator 30 then actuates the hit indicator 32 to give animmediate hit indication to the trainee firing the weapon but alsoactivates the kill .beam laser 28 which produces a broad angle kill beam42. The latter actuates the 360 kill receiver-actuator 16 on the helmet14 of the man target which in turn activates an alarm means 18 on theman target indicating to him that he is out of action.

Considering now details of circuitry suitable to implement the functionsdescribed above, reference is made initially to FIG. 2. The rifletrigger switch 24 when closed activates a laser pulser and galliumarsenide laser diode 27 which together with collimating lens 23constitute the fire beam laser 26 of FIG. 1. Squeezing the triggerswitch 24 thus initiates the firing of the narrow fire beam 38 at themantarget 12. If the narrow fire beam pulse 38 strikes theretroreflective target 12, it is reflected back to the hitreceiveractuator which comprises an interference filter 44, collectinglens 46, avalanche photo diode 50, transimpedance amplifier 52 and an RCfilter-comparator circuit, indicated generally at 54. The retroreflectedfire pulse 40 is filtered, collected and focused on the avalanche photodiode via the filter 44 and the collecting lens 46, the photo diode 50being a high gain detector and the output thereof is amplified by thetransimpedance amplifier 52. To prevent noise signals from affecting hitindication and count, the output of the amplifier 52 is thresholddetected by a voltage comparator circuit 54. Comparator circuit 54includes an adjustable reference voltage source provided from referencevoltage V and potentiometers 56 and 58 connected to ground as indicated.An RC circuit including capacitor 60 and resistor 62 is provided tocouple the amplifier 52 to comparator 54.

When the output from the amplifier 52 exceeds the set reference voltage,thus eliminating noise signals up to that set level, the voltagecomparator 54 generates a logical one signal pulse which is passed vialine 64 as one input to an AND gate 66 which forms part of the gatingcircuit means 36. The other portion of the gating circuit means 36includes a current transformer 68 and one shot range gate(multivibrator) 70. The current pulse from the laser pulser is sensed bythe current transformer 68 which triggers the one shot multivibra' torrange gate 70 which in turn provides a logical one input as a secondinput to the AND gate 66 for a time duration equivalent to the weaponsmaximum range. That is, the range gate multivibrator holds the AND gatein potential conducting condition for a time period up to that timewhich would match the ballistic flight time at maximum range.

In end result then, if the ones from reflected target pulse and rangegate current transformer pulse are present simultaneously at the twoinputs to AND gate 66, the AND gate 66 generates a one at its output.

This AND gate signal triggers three actions. First, the rifle asindicated in FIG. 1 and in FIG. 2 is provided with a lamp, actually alight emitting diode (LED) 32, and the output signal from gate 66activates a timer 72 which activates the LED hit indicator 32 on therifle sight. Secondly, the rifle is, in a preferred embodiment, providedwith a hit counter 76 which can be built into the rifle stock and whichprovides a record of target hits. Thirdly, the output signal from theAND gate 66 triggers the kill beam (broad beam) laser 28. Laser 28comprises a laser pulser 78, gallium arsenide diode 80 and collimatinglens 82, and produces the diverging broad angle kill beam 42 which inturn actuates the 360 kill receiver-actuator 16 (FIG. 1) on the helment14 of the man target 12 and turns on the hit alarm 18 indicating to theman target and to referees that the man is out of action.

The kill receiveractuator 16 may comprise four photodiode detectorslocated on four sides ofa rectangular box type holder in turn mounted onthe helmet 14 as shown in FIG. 1. The number of detectors on the helmetcan be reduced from four ifa prism or optical fiber means are utilized.

One suitable receiver and alarm circuit for the helmet receiverequipment is shown in FIG. 4. The circuit comprises a photo diode 84coupled to a comparator circuit 86 via an operational amplifier 88operating in the current to voltage amplifier mode and a voltage gainamplifier 90. The remainder of the circuit comprises an alarm, whichcould be a horn 92 operated through a silicon-controlled rectifier (SCR)94 which is actuated to on condition responsive to the output signal ofthe voltage comparator 86 and to of condition by operating a key switchindicated at 96.

When the kill beam laser pulse 42 (FIG. 4) is received by the diode 84the amplifier 88 is actuated via the capacitor coupling 98. The outputof the amplifier 88 acting as a current to voltage converter is invertedand further amplifier in the series connected second operationalamplifier 90. Capacitor coupling 91 is provided to ac (alternatingcurrent) couple the two amplifiers. Capacitor 89 connected to groundindicated provides a noise filter and the ratio of resistance values offeedback resistor 95 and series resistor 93 determines the voltage gain.The high speed voltage comparator 86, responsive to an input fromamplifier 90 on input line 100, produces a high output voltage when theinput voltage exceeds the reference voltage (indicated). The

reference voltage is set just above noise level by a potentiometer 102in the referencelevel circuit. The high voltage output when produced bythe comparator 86 is passed via diode 104 and lines 106, 108, and 112 tothe base 93 of SCR 94 to trigger the latter to on condition. The voltagedrop across resistor 114 actuates the hit alarm 92 which could be anaudio or visual alarm. A key is required to operate the switch 96 toshut the alarm off. It is contemplated that this key will be a keyremovable from the rifle circuit as indicated at 116 in FIG. 2 such thatthe rifle held by the man hit is thereafter inoperative. When switch 96is opened the SCR 94 is turned off and the alarm 92 is inactivated.

In FIG. 3 is shown a schematic of a suitable amplifier 52 and diodedetector 50 of'FIG. 2. The avalanche photo diode is a high-impedancedevice with avalanche gain. The avalanche detector is a current source.The detector 50 output goes to a low-noise high-speed transimpedanceamplifier 52 designed for current sources. The amplifier 52 provides anoutput voltage which is linearly proportional to the detectors inputcurrent.

In reference to the timer 72 and LED 32 shown in FIG. 2, a suitabletimer is the Signetics 555 1C Timer, and a suitable circuit forconnecting the same to the LED is shown in detail in FIG. 5, includingsuitable element values.

In the FIGS. 2 through 5, specific values of suitable elements areprovided.

It will be understood that various changes in the details, values andarrangement of parts, which have been herein described and illustratedin order to explain the nature of the invention, may be made by thoseskilled in the art wihin the principle and scope of the invention asexpressed in the appended claims.

What is claimed is:

1. A weapon fire kill simulator system comprising:

a. laser transmitter means for producing a narrow fire beam and a wideangle kill beam,

b. laser power source means and hit detectoractuator means,

c. a weapon having a trigger switch and means for mounting all saidabove mentioned means integral with said weapon and in position todirect said laser means and said hit detector-actuator means in thedirection in which said weapon is aimed,

. a man target carrying equipment including apparel or patches ofretroreflective material, a 360 kill beam detector-actuator means and analarm systern actuated from said kill detector-actuator means uponenergization of the latter,

e. said laser means being connected for producing said fire beam whensaid trigger switch is closed to direct said fire beam to said targetand a retroreflected fire beam from said apparel to said hit de-'tector-actuator means,

f. said hit detector-actuator means being connected to actuate saidlaser means to produce said wide angle kill beam to actuate said killdetectoractuator and hence said alarm system.

. Apparatus according to claim 1, including a. hit indicator means fixedto said weapon and con nccted to respond to actuation of said hitreceiveractuator to indicate a hit to a trainee firing said weapon. 7

3. Apparatus according to claim 2, in which a. said hit indicator meansincludes a light emitting diode counter and a light emitting diodevisible lamp. both fixed to said weapon.

4. Apparatus according to claim 1, including a. AND gate means, b. rangegate means comprising a timing pulse source connected to provide aninitiating actuating pulse to said laser transmitter means responsive toactuation of said trigger pulse and an additional pulse of selected timelength commensurate with the range of said weapon and provided as anenabling input to said AND gate to exclude from said hit indicator meansany hit signal whose propagation time delay is greater than the time oflaser pulse return from maximum target range of the weapon beingsimulated.

5. Apparatus according to claim 1, a. said hit receiver-actuatorincluding a voltage comparator with adjustable reference voltage inputto selectively adjust the sensitivity of said hit receiveractuator toamplify only target hit signals and exclude noise level signals up tothe strength of a target hit signal.

6. Apparatus according to claim 5, a. said hit receiver-actuatorincluding an avalanche type detector and amplifying means connected toprovide a hit signal input to said voltage comparator.

7. Apparatus according to claim 6, including a. AND gate means, b. rangegate means comprising a timing pulse source 8. Apparatus according toclaim 1, a. said laser transmitter means being two laser transmittersrespectively for said hit and kill beams.

9. Apparatus according to claim 1, a. said laser transmitter means beinga single laser of dual mode capability for producing said'hit and killbeams.

1. A weapon fire kill simulator system comprising: a. laser transmittermeans for producing a narrow fire beam and a wide angle kill beam, b.laser power source means and hit detector-actuator means, c. a weaponhaving a trigger switch and means for mounting all said above mentionedmeans integral with said weapon and in position to direct said lasermeans and said hit detectoractuator means in the direction in which saidweapon is aimed, d. a man target carrying equipment including apparel orpatches of retroreflective material, a 360* kill beam detector-actuatormeans and an alarm system actuated from said kill detectoractuator meansupon energization of the latter, e. said laser means being connected forproducing said fire beam when said trigger switch is closed to directsaid fire beam to said target and a retroreflected fire beam from saidapparel to said hit detector-actuator means, f. said hitdetector-actuator means being connected to actuate said laser means toproduce said wide angle kill beam to actuate said kill detector-actuatorand hence said alarm system.
 2. Apparatus according to claim 1,including a. hit indicator means fixed to said weapon and connected torespond to actuation of said hit receiver-actuator to indicate a hit toa trainee firing said weapon.
 3. Apparatus according to claim 2, inwhich a. said hit indicator means includes a light emitting diodecounter and a light emitting diode visible lamp, both fixed to saidweapon.
 4. Apparatus according to claim 1, including a. AND gate means,b. range gate means comprising a timing pulse source connected toprovide an initiating actuating pulse to said laser transmitter meansresponsive to actuation of said trigger pulse and an additional pulse ofselected time length commensurate with the range of said weapon andprovided as an enabling input to said AND gate to exclude from said hitindicator means any hit signal whose propagation time delay is greaterthan the time of laser pulse return from maximum target range of theweapon being simulated.
 5. Apparatus according to claim 1, a. said hitreceiver-actuator including a voltage comparator with adjustablereference voltage input to selectively adjust the sensitivity of saidhit receiver-actuator to amplify only target hit signals and excludenoise level signals up to the strength of a target hit signal. 6.Apparatus according to claim 5, a. said hit receiver-actuator includingan avalanche Type detector and amplifying means connected to provide ahit signal input to said voltage comparator.
 7. Apparatus according toclaim 6, including a. AND gate means, b. range gate means comprising atiming pulse source connected to provide an initiating actuating pulseto said laser transmitter means responsive to actuation of said triggerpulse and an additional pulse of selected time length commensurate withthe range of said weapon and provided as an enabling input to said ANDgate to exclude from said hit indicator means any hit signal whosepropagation time delay is greater than the time of laser pulse returnfrom maximum target range of the weapon being simulated.
 8. Apparatusaccording to claim 1, a. said laser transmitter means being two lasertransmitters respectively for said hit and kill beams.
 9. Apparatusaccording to claim 1, a. said laser transmitter means being a singlelaser of dual mode capability for producing said hit and kill beams.